/* ============================================================
   Practice Exam — modern minimal design system
   ============================================================ */

:root {
  /* Type */
  --font-sans: 'Inter', ui-sans-serif, system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-serif: 'Fraunces', 'Iowan Old Style', Georgia, serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, monospace;

  /* Neutrals — warm-cool paper whites + charcoals */
  --paper: oklch(0.985 0.004 80);
  --paper-2: oklch(0.965 0.005 80);
  --paper-3: oklch(0.945 0.006 80);
  --ink: oklch(0.22 0.012 260);
  --ink-2: oklch(0.36 0.012 260);
  --ink-3: oklch(0.52 0.012 260);
  --ink-4: oklch(0.68 0.008 260);

  --line: oklch(0.9 0.006 80);
  --line-2: oklch(0.86 0.008 80);
  --line-3: oklch(0.78 0.01 80);

  /* Accent — single restrained indigo */
  --accent: oklch(0.55 0.15 265);
  --accent-weak: oklch(0.94 0.03 265);
  --accent-ink: oklch(0.38 0.14 265);

  /* Semantic */
  --correct: oklch(0.58 0.13 150);
  --correct-weak: oklch(0.95 0.03 150);
  --wrong: oklch(0.58 0.18 25);
  --wrong-weak: oklch(0.96 0.03 25);
  --warn: oklch(0.72 0.15 75);

  /* Rhythm */
  --r-xs: 4px;
  --r-sm: 6px;
  --r-md: 10px;
  --r-lg: 14px;

  --shadow-sm: 0 1px 0 oklch(0.9 0.005 80 / 0.6);
  --shadow-md: 0 1px 2px oklch(0 0 0 / 0.04), 0 4px 16px oklch(0 0 0 / 0.04);
}

[data-theme="dark"] {
  --paper: oklch(0.18 0.012 260);
  --paper-2: oklch(0.22 0.013 260);
  --paper-3: oklch(0.26 0.013 260);
  --ink: oklch(0.96 0.005 80);
  --ink-2: oklch(0.82 0.008 80);
  --ink-3: oklch(0.68 0.008 80);
  --ink-4: oklch(0.52 0.008 80);
  --line: oklch(0.3 0.012 260);
  --line-2: oklch(0.36 0.012 260);
  --line-3: oklch(0.44 0.012 260);
  --accent: oklch(0.72 0.13 265);
  --accent-weak: oklch(0.28 0.06 265);
  --accent-ink: oklch(0.85 0.12 265);
  --correct-weak: oklch(0.28 0.06 150);
  --wrong-weak: oklch(0.28 0.06 25);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
  font-family: var(--font-sans);
  font-feature-settings: 'ss01', 'cv11';
  background: var(--paper);
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
  font-size: 15px;
  line-height: 1.55;
  letter-spacing: -0.005em;
}

button { font-family: inherit; }
input, textarea, select { font-family: inherit; font-size: inherit; color: inherit; }

/* Utility */
.mono { font-family: var(--font-mono); font-feature-settings: 'zero'; letter-spacing: 0; }
.serif { font-family: var(--font-serif); }
.hairline { border: 1px solid var(--line); }
.muted { color: var(--ink-3); }
.faint { color: var(--ink-4); }

/* ---------- Button ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 14px;
  border-radius: var(--r-md);
  border: 1px solid var(--line-2);
  background: var(--paper);
  color: var(--ink);
  font-size: 13.5px;
  font-weight: 500;
  letter-spacing: -0.005em;
  cursor: pointer;
  transition: background 120ms ease, border-color 120ms ease, color 120ms ease;
}
.btn:hover { background: var(--paper-2); border-color: var(--line-3); }
.btn:active { background: var(--paper-3); }
.btn[disabled] { opacity: 0.4; cursor: not-allowed; }

.btn-primary {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}
.btn-primary:hover { background: var(--ink-2); border-color: var(--ink-2); }

.btn-ghost {
  border-color: transparent;
  background: transparent;
}
.btn-ghost:hover { background: var(--paper-2); }

.btn-sm { padding: 6px 10px; font-size: 12.5px; }

/* ---------- Inputs ---------- */
.input, .textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-md);
  background: var(--paper);
  color: var(--ink);
  outline: none;
  transition: border-color 120ms ease, box-shadow 120ms ease;
}
.input:focus, .textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-weak);
}
.textarea { resize: vertical; min-height: 120px; line-height: 1.6; }

/* ---------- Layout ---------- */
.shell {
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 100vh;
}

.topbar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px 28px;
  border-bottom: 1px solid var(--line);
  background: var(--paper);
  position: sticky; top: 0; z-index: 10;
}

.brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 600;
  letter-spacing: -0.02em;
  font-size: 15px;
}
.brand-mark {
  width: 22px; height: 22px;
  border: 1.5px solid var(--ink);
  border-radius: 5px;
  position: relative;
  display: inline-block;
}
.brand-mark::after {
  content: '';
  position: absolute;
  inset: 4px 8px 4px 4px;
  background: var(--ink);
  border-radius: 1px;
}

.topbar-meta {
  display: flex; align-items: center; gap: 16px;
  margin-left: auto;
  color: var(--ink-3);
  font-size: 13px;
}

/* ---------- Landing ---------- */
.landing {
  max-width: 1080px;
  margin: 0 auto;
  padding: 72px 32px 120px;
}
.landing-eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-3);
  margin-bottom: 24px;
}
.landing-title {
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(40px, 6vw, 68px);
  line-height: 1.02;
  letter-spacing: -0.028em;
  color: var(--ink);
  margin: 0 0 20px;
  text-wrap: pretty;
  max-width: 18ch;
}
.landing-title em {
  font-style: italic;
  color: var(--accent);
  font-variation-settings: 'SOFT' 100;
}
.landing-sub {
  font-size: 17px;
  color: var(--ink-2);
  max-width: 58ch;
  margin: 0 0 48px;
  line-height: 1.55;
}

.landing-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 48px;
  align-items: start;
}

.dropzone {
  border: 1.5px dashed var(--line-3);
  border-radius: var(--r-lg);
  padding: 40px 32px;
  text-align: center;
  background: var(--paper-2);
  transition: all 150ms ease;
  cursor: pointer;
}
.dropzone:hover, .dropzone.drag-over {
  border-color: var(--accent);
  background: var(--accent-weak);
}
.dropzone-icon {
  width: 40px; height: 40px;
  margin: 0 auto 16px;
  border: 1.5px solid var(--ink-3);
  border-radius: 8px;
  position: relative;
}
.dropzone-icon::before, .dropzone-icon::after {
  content: '';
  position: absolute;
  background: var(--ink-3);
}
.dropzone-icon::before {
  width: 2px; height: 14px;
  top: 10px; left: 50%;
  transform: translateX(-50%);
}
.dropzone-icon::after {
  width: 10px; height: 2px;
  top: 16px; left: 50%;
  transform: translateX(-50%) rotate(45deg);
  transform-origin: left center;
  box-shadow: -12px 0 0 var(--ink-3);
}
.dropzone h3 {
  margin: 0 0 6px;
  font-weight: 500;
  font-size: 16px;
}
.dropzone p {
  margin: 0;
  color: var(--ink-3);
  font-size: 13.5px;
}

.samples h4 {
  font-size: 11px;
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-3);
  margin: 0 0 14px;
  font-weight: 500;
}
.sample {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 16px;
  border-radius: var(--r-md);
  border: 1px solid var(--line);
  margin-bottom: 8px;
  cursor: pointer;
  background: var(--paper);
  transition: all 120ms ease;
}
.sample:hover {
  border-color: var(--line-3);
  background: var(--paper-2);
}
.sample-mark {
  width: 36px; height: 36px;
  border-radius: 8px;
  background: var(--paper-3);
  display: grid; place-items: center;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--ink-2);
  flex-shrink: 0;
}
.sample-body { flex: 1; min-width: 0; }
.sample-title { font-weight: 500; font-size: 14.5px; margin-bottom: 2px; }
.sample-meta { font-size: 12.5px; color: var(--ink-3); }
.sample-arrow { color: var(--ink-4); align-self: center; }

.history {
  margin-top: 56px;
  padding-top: 40px;
  border-top: 1px solid var(--line);
}
.history-row {
  display: grid;
  grid-template-columns: 1fr auto auto auto;
  gap: 24px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
  align-items: center;
  font-size: 13.5px;
}
.history-row:last-child { border-bottom: none; }
.history-title { font-weight: 500; }
.score-pill {
  font-family: var(--font-mono);
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--paper-3);
  font-size: 12px;
  color: var(--ink-2);
}
.score-pill.pass { background: var(--correct-weak); color: var(--correct); }
.score-pill.fail { background: var(--wrong-weak); color: var(--wrong); }

/* ---------- Exam Layout ---------- */
.exam-shell {
  display: grid;
  grid-template-columns: 280px 1fr 280px;
  min-height: calc(100vh - 57px);
}

.sidebar {
  border-right: 1px solid var(--line);
  padding: 24px 20px;
  background: var(--paper);
  overflow-y: auto;
  position: sticky; top: 57px;
  max-height: calc(100vh - 57px);
}
.sidebar-title {
  font-family: var(--font-serif);
  font-size: 22px;
  letter-spacing: -0.015em;
  margin: 0 0 4px;
  line-height: 1.15;
}
.sidebar-sub {
  font-size: 12.5px;
  color: var(--ink-3);
  margin: 0 0 24px;
}
.sidebar-section-label {
  font-family: var(--font-mono);
  font-size: 10.5px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-4);
  margin: 24px 0 10px;
  font-weight: 500;
}
.nav-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.nav-item {
  display: grid;
  grid-template-columns: 28px 1fr auto;
  align-items: center;
  gap: 10px;
  padding: 7px 10px;
  border-radius: var(--r-sm);
  cursor: pointer;
  border: none;
  background: transparent;
  color: var(--ink-2);
  text-align: left;
  font-size: 13px;
  transition: background 100ms ease;
  width: 100%;
}
.nav-item:hover { background: var(--paper-2); }
.nav-item.active {
  background: var(--paper-3);
  color: var(--ink);
}
.nav-item-num {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--ink-4);
}
.nav-item.active .nav-item-num { color: var(--ink-2); }
.nav-item-title {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.nav-dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--line-2);
}
.nav-dot.answered { background: var(--accent); }
.nav-dot.flagged { background: var(--warn); }
.nav-dot.correct { background: var(--correct); }
.nav-dot.wrong { background: var(--wrong); }

.main {
  padding: 48px 64px 120px;
  overflow-y: auto;
  max-width: 920px;
  margin: 0 auto;
  width: 100%;
}

.meta-rail {
  border-left: 1px solid var(--line);
  padding: 24px 20px;
  background: var(--paper);
  position: sticky; top: 57px;
  max-height: calc(100vh - 57px);
  overflow-y: auto;
}
.meta-block { margin-bottom: 28px; }
.meta-label {
  font-family: var(--font-mono);
  font-size: 10.5px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-4);
  margin-bottom: 8px;
  font-weight: 500;
}
.meta-value {
  font-family: var(--font-serif);
  font-size: 26px;
  letter-spacing: -0.02em;
  line-height: 1.1;
}
.meta-value.mono { font-family: var(--font-mono); font-size: 18px; font-weight: 500; }

.progress-bar {
  height: 3px;
  background: var(--line);
  border-radius: 999px;
  overflow: hidden;
  margin-top: 10px;
}
.progress-bar > div {
  height: 100%;
  background: var(--ink);
  transition: width 200ms ease;
}

.timer-urgent { color: var(--wrong); }

/* ---------- Question Card ---------- */
.question-header {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--line);
}
.q-index {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-3);
  letter-spacing: 0.02em;
}
.q-category {
  font-size: 12px;
  color: var(--ink-3);
  padding: 2px 8px;
  background: var(--paper-3);
  border-radius: 4px;
  font-family: var(--font-mono);
}
.q-points {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-3);
}

.q-prompt {
  font-family: var(--font-serif);
  font-size: 26px;
  line-height: 1.35;
  letter-spacing: -0.015em;
  color: var(--ink);
  margin: 0 0 32px;
  text-wrap: pretty;
  font-weight: 400;
}
.q-prompt .katex { font-size: 1em; }

.q-media {
  margin: 0 0 32px;
  border-radius: var(--r-md);
  overflow: hidden;
  border: 1px solid var(--line);
}
.q-media img { width: 100%; display: block; }
.q-media-caption {
  padding: 10px 14px;
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  font-size: 12.5px;
  color: var(--ink-3);
  font-style: italic;
}

.q-code {
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  padding: 16px 20px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.6;
  margin: 0 0 32px;
  overflow-x: auto;
  white-space: pre;
}
.q-code .cm-keyword { color: oklch(0.5 0.18 280); font-weight: 500; }
.q-code .cm-string { color: oklch(0.55 0.12 140); }
.q-code .cm-number { color: oklch(0.55 0.14 40); }
.q-code .cm-comment { color: var(--ink-4); font-style: italic; }
.q-code .cm-fn { color: oklch(0.5 0.14 220); }

.q-table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 32px;
  font-size: 14px;
}
.q-table th, .q-table td {
  padding: 10px 14px;
  text-align: left;
  border-bottom: 1px solid var(--line);
}
.q-table th {
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ink-3);
  font-weight: 500;
  background: var(--paper-2);
}
.q-table tr:last-child td { border-bottom: 1px solid var(--line-2); }

.q-audio {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  background: var(--paper-2);
  border-radius: var(--r-md);
  border: 1px solid var(--line);
  margin: 0 0 32px;
}
.q-audio audio { flex: 1; }

/* ---------- Choices ---------- */
.choices { display: flex; flex-direction: column; gap: 8px; }
.choice {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px 20px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-md);
  cursor: pointer;
  transition: all 120ms ease;
  background: var(--paper);
  text-align: left;
  width: 100%;
  color: var(--ink);
  font-size: 15px;
  line-height: 1.5;
}
.choice:hover { border-color: var(--line-3); background: var(--paper-2); }
.choice.selected {
  border-color: var(--ink);
  background: var(--paper-2);
}
.choice.correct {
  border-color: var(--correct);
  background: var(--correct-weak);
}
.choice.wrong {
  border-color: var(--wrong);
  background: var(--wrong-weak);
}
.choice-marker {
  width: 22px; height: 22px;
  border: 1.5px solid var(--line-3);
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 1px;
  display: grid; place-items: center;
  position: relative;
  transition: all 120ms ease;
}
.choice.selected .choice-marker {
  border-color: var(--ink);
  background: var(--ink);
}
.choice.selected .choice-marker::after {
  content: '';
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--paper);
}
.choice-marker.square { border-radius: 5px; }
.choice.selected .choice-marker.square::after {
  width: 10px; height: 6px;
  border: 2px solid var(--paper);
  border-top: 0; border-right: 0;
  background: transparent;
  border-radius: 0;
  transform: rotate(-45deg) translate(1px, -1px);
}
.choice-key {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-4);
  margin-right: 8px;
}
.choice.selected .choice-key { color: var(--ink-2); }

/* ---------- Match ---------- */
.match-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  position: relative;
}
.match-col {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.match-col-label {
  font-family: var(--font-mono);
  font-size: 10.5px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-4);
  margin-bottom: 4px;
  font-weight: 500;
}
.match-item {
  padding: 14px 16px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-md);
  background: var(--paper);
  cursor: pointer;
  transition: all 120ms ease;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  font-size: 14px;
}
.match-item:hover { border-color: var(--line-3); background: var(--paper-2); }
.match-item.active {
  border-color: var(--accent);
  background: var(--accent-weak);
  box-shadow: 0 0 0 3px var(--accent-weak);
}
.match-item.paired {
  border-color: var(--ink-3);
  background: var(--paper-2);
}
.match-item.correct { border-color: var(--correct); background: var(--correct-weak); }
.match-item.wrong { border-color: var(--wrong); background: var(--wrong-weak); }
.match-pair-badge {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-3);
  padding: 2px 7px;
  background: var(--paper-3);
  border-radius: 999px;
  flex-shrink: 0;
}

/* ---------- Order ---------- */
.order-list { display: flex; flex-direction: column; gap: 8px; }
.order-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-md);
  background: var(--paper);
  cursor: grab;
  transition: all 120ms ease;
  font-size: 14.5px;
}
.order-item:hover { border-color: var(--line-3); background: var(--paper-2); }
.order-item.dragging { opacity: 0.4; }
.order-item.drop-before { border-top-color: var(--accent); box-shadow: 0 -2px 0 var(--accent); }
.order-item.drop-after { border-bottom-color: var(--accent); box-shadow: 0 2px 0 var(--accent); }
.order-handle {
  color: var(--ink-4);
  font-size: 16px;
  line-height: 1;
  cursor: grab;
  user-select: none;
}
.order-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-3);
  width: 20px;
  flex-shrink: 0;
}
.order-text { flex: 1; }
.order-item.correct { border-color: var(--correct); background: var(--correct-weak); }
.order-item.wrong { border-color: var(--wrong); background: var(--wrong-weak); }

/* ---------- Short / Math input ---------- */
.answer-input-wrap { display: flex; flex-direction: column; gap: 12px; max-width: 560px; }
.math-preview {
  padding: 14px 16px;
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  min-height: 48px;
  display: flex;
  align-items: center;
}
.math-preview-label {
  font-family: var(--font-mono);
  font-size: 10.5px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-4);
  margin-right: 12px;
}

/* ---------- Feedback block ---------- */
.feedback {
  margin-top: 32px;
  padding: 20px 24px;
  border-radius: var(--r-md);
  border-left: 3px solid var(--ink);
  background: var(--paper-2);
}
.feedback.correct { border-left-color: var(--correct); background: var(--correct-weak); }
.feedback.wrong { border-left-color: var(--wrong); background: var(--wrong-weak); }
.feedback-label {
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 600;
  margin-bottom: 8px;
}
.feedback.correct .feedback-label { color: var(--correct); }
.feedback.wrong .feedback-label { color: var(--wrong); }
.feedback-body {
  font-size: 14.5px;
  line-height: 1.6;
}
.feedback-body p { margin: 0 0 8px; }
.feedback-body p:last-child { margin-bottom: 0; }

/* ---------- Exam footer ---------- */
.exam-footer {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
}
.exam-footer .spacer { flex: 1; }

/* ---------- Results ---------- */
.results {
  max-width: 960px;
  margin: 0 auto;
  padding: 64px 32px 120px;
}
.results-eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-3);
  margin-bottom: 16px;
}
.results-title {
  font-family: var(--font-serif);
  font-size: 56px;
  font-weight: 400;
  letter-spacing: -0.025em;
  line-height: 1.05;
  margin: 0 0 48px;
}
.results-title em { font-style: italic; color: var(--accent); }

.score-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  margin-bottom: 56px;
}
.score-cell {
  padding: 28px 0;
  border-right: 1px solid var(--line);
}
.score-cell:last-child { border-right: none; }
.score-cell-label {
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-3);
  margin-bottom: 8px;
  font-weight: 500;
}
.score-cell-value {
  font-family: var(--font-serif);
  font-size: 48px;
  letter-spacing: -0.02em;
  line-height: 1;
  font-weight: 400;
}
.score-cell-unit {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--ink-3);
  margin-left: 4px;
}

.category-breakdown { margin-bottom: 56px; }
.category-row {
  display: grid;
  grid-template-columns: 180px 1fr 60px;
  gap: 16px;
  align-items: center;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
}
.category-row:last-child { border-bottom: none; }
.category-bar {
  height: 4px;
  background: var(--line);
  border-radius: 999px;
  overflow: hidden;
}
.category-bar > div { height: 100%; background: var(--ink); transition: width 400ms ease; }
.category-score {
  font-family: var(--font-mono);
  font-size: 12.5px;
  text-align: right;
  color: var(--ink-2);
}

.review-heading {
  font-family: var(--font-serif);
  font-size: 28px;
  letter-spacing: -0.02em;
  margin: 0 0 24px;
  font-weight: 400;
}

.review-item {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  margin-bottom: 16px;
  overflow: hidden;
}
.review-item-header {
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  cursor: pointer;
  background: var(--paper);
  border-bottom: 1px solid transparent;
}
.review-item.open .review-item-header { border-bottom-color: var(--line); }
.review-item-header:hover { background: var(--paper-2); }
.review-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-3);
  min-width: 36px;
}
.review-title {
  flex: 1;
  font-size: 14.5px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.review-status {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 999px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.review-status.correct { background: var(--correct-weak); color: var(--correct); }
.review-status.wrong { background: var(--wrong-weak); color: var(--wrong); }
.review-status.ungraded { background: var(--paper-3); color: var(--ink-3); }
.review-body {
  padding: 24px 28px;
  background: var(--paper-2);
  font-size: 14px;
}

/* ---------- Tweaks panel ---------- */
.tweaks-panel {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 280px;
  background: var(--paper);
  border: 1px solid var(--line-2);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-md);
  z-index: 100;
  overflow: hidden;
}
.tweaks-header {
  padding: 12px 16px;
  border-bottom: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 500;
  color: var(--ink-2);
}
.tweaks-body { padding: 16px; display: flex; flex-direction: column; gap: 16px; }
.tweak-row { display: flex; flex-direction: column; gap: 6px; }
.tweak-label { font-size: 12px; color: var(--ink-3); font-family: var(--font-mono); text-transform: uppercase; letter-spacing: 0.08em; }
.tweak-control {
  display: flex;
  gap: 4px;
  background: var(--paper-2);
  padding: 3px;
  border-radius: var(--r-sm);
  border: 1px solid var(--line);
}
.tweak-seg {
  flex: 1;
  padding: 6px 10px;
  border: none;
  background: transparent;
  border-radius: 4px;
  font-size: 12px;
  cursor: pointer;
  color: var(--ink-2);
  text-align: center;
}
.tweak-seg.active { background: var(--paper); color: var(--ink); box-shadow: var(--shadow-sm); }

/* Keyboard hints */
.kbd {
  font-family: var(--font-mono);
  font-size: 10.5px;
  padding: 2px 6px;
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 4px;
  color: var(--ink-3);
}

/* Scrollbar */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--line-2); border-radius: 999px; border: 2px solid var(--paper); }
::-webkit-scrollbar-thumb:hover { background: var(--line-3); }

/* Selection */
::selection { background: var(--accent-weak); color: var(--accent-ink); }

/* Responsive */
@media (max-width: 1100px) {
  .exam-shell { grid-template-columns: 240px 1fr; }
  .meta-rail { display: none; }
}
@media (max-width: 760px) {
  .exam-shell { grid-template-columns: 1fr; }
  .sidebar { position: relative; max-height: none; }
  .main { padding: 32px 20px 120px; }
  .landing-grid { grid-template-columns: 1fr; }
  .score-grid { grid-template-columns: 1fr; }
  .score-cell { border-right: none; border-bottom: 1px solid var(--line); }
}